(1) Field of the Invention
The present invention relates to a molding reinforced polyamide composition which is excellent in heat resistance characteristics, mechanical properties, chemical and physical properties and molding characteristics.
(2) Description of the Prior Art
Ordinarily, thermoplastic resins such as polyolefins, polyesters and polyamides can be applied to melt molding such as compression molding, injection molding or extrusion molding and they are excellent in the moldability. However, these resins are not satisfactory as engineering plastics in heat resistance characteristics, mechanical properties and chemical properties, but they are used in the general-purpose molding field while utilizing excellent characteristics of the respective resins. As means for improving heat resistance characteristics, mechanical properties or physical and chemical properties in thermoplastic resin, there have been proposed compositions formed by incorporating in these thermoplastic resins fillers such as glass powder, graphite powder, glass fiber and carbon fiber. The foregoing characteristics are considerably improved in these filler-incorporated reinforced thermoplastic resin compositions. However, the characteristics of these reinforced compositions are still lower than the levels required for high-performance engineering plastics, and as in case of the above-mentioned ordinary thermoplastic resins, these reinforced thermoplastic resin compositions are used only in the molding field where the characteristics of the respective resins are utilized.
As known engineering plastics excellent in heat resistance characteristics, mechanical properties and chemical and physical properties, there can be mentioned polytetrafluoroethylene (Teflon.RTM.), polyparaphenylene-terephthalamide (Keblar.RTM.), polyimide composed of a condensate of 4,4'-diaminodiphenyl ether with pyromellitic anhdyride (Kapton.RTM.), polyhexamethyleneadipoamide (6,6-nylon), poly-2,2,4-trimethylhexamethylene-terephthalamide (Trogamid.RTM.), polyphenylene-sulfide and polyacetal. Among these plastics, polytetrafluoroethylene, polyterephthaloylparaphenylene-diamine and the above-mentioned polyimide resin are excellent in heat resistance characteristics, mechanical properties and chemical and physical properties, but they are defective in that melt molding is impossible and therefore, the utilization field is extremely limited. Among the foregoing engineering plastics, polyphenylene-sulfide, polyhexamethyleneadipoamide (6,6-nylon), 2,2,4-trimethylhexamethylene-terephthalamide (Trogamid.RTM.) and polyacetal are characterized in that melt molding is possible. However, these plastics are insufficient in several points. More specifically, polyamides such as polyhexamethylene adipoamide (6,6-nylon) and poly-2,2,4-trimethylhexamethylene-terephthalamide (Trogamid.RTM.) are inferior in heat resistance characteristics such as the glass transition point and heat distortion temperature, mechanical properties such as the tensile strength, flexural strength and abrasion resistance and chemical and physical properties such as the chemical resistance, boiling water resistance and saturated water absorption, and polyacetal is inferior in heat resistance characteristics such as the melting point and heat distortion temperature and mechanical properties such as the flexural strength, impact strength and abrasion resistance.